Junko Hosoe is a race commentator, reflecting her real-world profession. Her background includes being one of Japan's first female jockeys in the 1990s; she retired from riding in 2001 after 493 races due to health reasons, subsequently transitioning to commentary.

During races, she focuses commentary on horse health and pre-race conditions, positioned near the starting gates. She gained notice for her vocal reaction to an incident involving Gold Ship at the 2015 Takarazuka Kinen. Her commentary style carries distinctive weight and authenticity, punctuated by signature calls like "Run, Suzuka!".

Her appearance presents a mature demeanor with gentle upturned light blue eyes, pink lipstick, and short black hair swept right. She wears a royal blue blouse with a gold shoulder pendant and pearl necklace, a white skirt, black leggings, and royal blue heels adorned with pearls.

Within the spin-off *Umayuru*, she appears in chibi-style operating Bar HosoJun, a parody of her real-life YouTube channel "Snack Zunko." She also provides commentary within the game's "Make a new track!!" scenario and is referenced in promotional art books, though only her chibi depiction features in *Umayuru*-related content. Her character portrayal consistently emphasizes her professional commentary background.